title: Isoprene emission protects photosynthesis but reduces plant productivity during drought in transgenic tobacco (Nicotiana tabacum) plants.
abstract: Isoprene protects the photosynthetic apparatus of isoprene-emitting plants from oxidative stress. The role of isoprene in the response of plants to drought is less clear. Water was withheld from transgenic isoprene-emitting and non-emitting tobacco (Nicotiana tabacum) plants, to examine: the response of isoprene emission to plant water deficit; a possible relationship between concentrations of the drought-induced phytohormone abscisic acid (ABA) and isoprene; and whether isoprene affected foliar reactive oxygen species (ROS) and lipid peroxidation levels. Isoprene emission did not affect whole-plant water use, foliar ABA concentration or leaf water potential under water deficit. Compared with well-watered controls, droughted non-emitting plants significantly increased ROS content (31-46%) and lipid peroxidation (30-47%), concomitant with decreased operating and maximum efficiencies of photosystem II photochemistry and lower leaf and whole-plant water use efficiency (WUE). Droughted isoprene-emitting plants showed no increase in ROS content or lipid peroxidation relative to well-watered controls, despite isoprene emission decreasing before leaf wilting. Although isoprene emission protected the photosynthetic apparatus and enhanced leaf and whole-plant WUE, non-emitting plants had 8-24% more biomass under drought, implying that isoprene emission incurred a yield penalty.
authors.affiliation: Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK.
authors.forename: Annette C
authors.initials: AC
authors.lastname: Ryan
authors.affiliation: Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK.
authors.forename: C Nicholas
authors.initials: CN
authors.lastname: Hewitt
authors.affiliation: Faculty of Agriculture and Environment, The University of Sydney, Sydney, NSW, 2006, Australia.
authors.forename: Malcolm
authors.initials: M
authors.lastname: Possell
authors.affiliation: Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Qld, 4072, Australia.
authors.forename: Claudia E
authors.initials: CE
authors.lastname: Vickers
authors.affiliation: Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK.
authors.forename: Anna
authors.initials: A
authors.lastname: Purnell
authors.affiliation: School of Biological Sciences, University of Essex, Colchester, CO4 3SQ, UK.
authors.forename: Philip M
authors.initials: PM
authors.lastname: Mullineaux
authors.affiliation: Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK.
authors.forename: William J
authors.initials: WJ
authors.lastname: Davies
authors.affiliation: Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK.
authors.forename: Ian C
authors.initials: IC
authors.lastname: Dodd
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D018533:Biomass; D002070:Butadienes / Q000378:metabolism*; D055864:Droughts; D045782:Hemiterpenes / Q000378:metabolism*; D015227:Lipid Peroxidation; D018384:Oxidative Stress; D010420:Pentanes / Q000378:metabolism*; D010788:Photosynthesis; D045332:Photosystem II Protein Complex / Q000378:metabolism; D010937:Plant Growth Regulators / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism / Q000502:physiology; D030821:Plants, Genetically Modified; D017382:Reactive Oxygen Species / Q000378:metabolism; D014026:Nicotiana / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D014867:Water / Q000502:physiology*
chemical_list: D002070:Butadienes; D045782:Hemiterpenes; D010420:Pentanes; D045332:Photosystem II Protein Complex; D010937:Plant Growth Regulators; D017382:Reactive Oxygen Species; D014867:Water; C005059:isoprene; D000040:Abscisic Acid
keywords: Nicotiana tabacum (tobacco); abscisic acid (ABA); drought; hydrogen peroxide; isoprene; lipid peroxidation; oxidative stress; water use efficiency